Radio tube holder and extractor



May 25? 1943.v

R; s`. MERKLE RADIO TUBE HOLDER AND EXTRAQTOR l Filed Non 22, 1941`INVENTOR MEE/(LE BY v ORY ,au PH s.

Patented May 25, 1943 mimo TUBE HOLDER AND EXTRACTOR Ralph S. Merkle,Emporium, Pa.; assgnor to Syl- Vania Electric Products Inc., acorporation of Massachusetts Application November 22, 1941, Serial No.420,143

6 Claims.

This invention refers to extracting implements, and in particular toimplements for removing devices such as radio tubes or lamp bulbs fromtheir sockets. f

In servicing and in trouble-shooting of radio sets, it is frequentlynecessary to remove tubes from their sockets for testing.

The tubes are usually spaced closely to each other or to other circuitelements in the chassis, and are, therefore, not alway easily accessiblefor gripping by the hand; and it is particularly difficult if not oftenimpossible to grip the base of the tube'for removing it from its socket,as is necessary with certain tube types.

y In the latter case, it is necessary to apply the fingers to the tubeenvelope, and the pressure necessary for obtaining a rm grip on theenvelope, so as to be able to rel-ease the contact pins from the socket,may damage the envelope. In some cases the envelope will be loosenedfrom the basing cement before the friction between the base pins and thesocket can be overcome.

Generally, the first step in trouble-shooting is a performance test ofthe radio set, from which the service men may gain indications for thepossible causes of the unsatisfactory performance. During thisperformance test the tubes will become hot, and the tube temperature maybecome too high for comfortable direct contact with the hand.

Thus the operator will either lose time by Waiting for the tube to coolsufficiently, or he may use a handkerchief or other heat insulatingsheath between his hand and the tube envelope. This is not good practicebecause it obstructs the visual observance of adjacent equipment;decreases the friction between hand and tube; and

weakens the sense of touch necessary for controlling the pulling.Furthermore, during the pulling the heat may penetrate the handkerchiefsuflieiently to give a sudden sting to the fingers, and in connectionwith the other contributing causes for lessened active control of thetube removal, the tube may drop to the door and break or becomeinoperative.

The appropriate location at the tube for the application of the pullingforce is, in any event, the tube base, and a number of tube pullers areknown, which can be used for applying the pull at the proper place. Mostof these known devices are built similar to pliers, which have to bekept closed by the hand that performs the pulling. The jaws of thesepliers are either formed as semi-cylinders, surrounding the base of thetube, or as wedges to be inserted under the base.

This known type of tube puller has several disadvantages. It is notconvenient to compress the two handles of a pair of pliers while pullingat the same time. Furthermore, the conventional radio cabinets are nothigh enough to allow the Whole hand of the operatorto enter togetherwith the pliers; or at least not high enough to provide sufficientclearance to cornplete the pulling out motion after the pliers areinserted. It ,thus becomes necessary to remove the chassis from most bfthe radio cabinets before it is possible to use one of the plier-liketube pullers. f

It is, therefore, a main object of the invention to provide a radio tubepuller which allows in most practical cases, the removal of radio tubesfrom their sockets without rst removing the chassis from the radiocabinet.

Another object of the invention is to provide a radio tube puller whichmay be operated with one finger only and does not require the Oppositionof the thumb and at least two :other fingers for obtaining a firm gripon the base of a radio tube or for pulling. Y

1 A' feature of the invention refers to a slotted Vring-shaped elastictube base holder, as a part of the tube puller, which may beconveniently slipped on the tube for inserting but will offer enoughfriction for pulling the tube out `of its socket.

It is a further main object of the invention to provide a. tube pullerfor tubes known in the trade as Sylvania Lock-in tubes, which may beremoved by a tilting of the tube in the socket, whereby the lockingspring which engages the groove in the center pin of the tube may bedisengaged from this groove.

A feature of the invention refers to the increase in the lever arm to alength greateithan thebase radius of the tube, which is provided by theflared shape of the bottom part of the tube puller, whereby the forceneeded for tilting the tube against the socket axis-is reduced.

Another feature of the invention refers to the elasticvgrip of the baseholding ring, which prevents a. dropping of the tube after the latterhas been removed from the socket.

A further feature of the invention refers to application of a buffersuch as a rubber padding ring over the handle, which prevents a highlocal pressure between the envelope and handle of the tube puller duringthe pulli-ng operation.

An additional feature of the'invention consists in the increasedfriction between the tube envelope and the tube puller oiiered by therubber buffer on the handle.

The invention will now be described in detail in connection with theattached drawing, in which Fig. 1 shows the tube puller and a lock-intube as it is about to be inserted.

Fig. 2 shows the tube puller ready in position for pulling the tube.

Fig. 3 is a top1plan view of Fig. 2.

Fig. 4 illustrates the tilting motion of the puller by which a lock-intube is removed from its socket.

Fig. 5 is an enlarged diagrammatic View of part of Fig. 4. Y

The tube puller according to the invention consists of a slottedcylindrical metal ring I, whose inner diameter in the normal orunstretched state is slightly smaller th-an that of the base 1 of thetube to be pulled. The ring is made elastic, so it will open up a littleat the slot 3 (see Fig. 3) when it is forced down over the base 'I oftube 8. A handle 2 is, at its lower end, welded to ring I, the top 9 ofthe handle being bent for insertion of a finger.

A padding ring I2, made of rubber, neoprene or any other suitablematerial may be slipped over the handle and located at a place asindicated in the drawing. This padding ring serves two purposes. velopefrom direct contact with the `handle 2, which might occur during thetilting operation indicated in Fig, 4. Second it helps, in addition, toincrease the friction between tube envelope and the puller and preventsa dropping of` the tube from the puller after removal from the set ifthe puller has not been inserted all the way down to the socket. Itshould be observed that the ring I2 is suiiciently thick so that when inplace it overlies the upper edge of ring I sufficiently far so as topress against the bulb 8.

There is shown in the 4drawing one well-known type of radio tubeidentified in the trade as 2. Sylvania Lock-In type having a series ofcontact pins 4 arranged in a circle at the bottom of lthe tube andsurrounding a central metal keying boss 5 which is fastened to the metaltube base The boss 5 is provided at its lower end with acircumferentialgroove B. lThe drawing also shows the tube plugged-in to a suitablesocket I0, having a series of circularly arranged contact prongs (notshown)` to receive the pins 4 and a central split cylindrical collar IIto receive the member 5. The collar lI has adjacent its lower end aninward offset as indicated by the numeral I3 which -oiTsezt issurrounded by a split spring ring I4 which tends to hold the member IIat a reduced diameter. When the tube is fully plugged into the socket,the Offset portion I3 engages the groove 6 wherein itis locked by meansof the spring ring I4. With this type of construction, in or-der toremove the tube from the socket, it is necessary to .tilt the tubeslightly with respect to its Vertical axis so as to vdiseng-age theoffset I3 from the groove 6 whereupon the tube may be restored to itsvertical position and pulled from 4the socket. In order to 'effect thisdisengagement of parts 6 and I3, without using the tube-puller of theinvention, the lower corner edge of the tube base is used as a fulcrumso that the leverage is determined by the radius A (Fig. 4). When thepuller 2 is used to remove the tube, it is inserted on to the tube baseas shown in Figs. l and 2. Ordinarily, the base 'I is provided with aVsmall smoothly rounded boss I6.

First it protects the tube en- Consequently, when the member 2 is pusheddownwardly along the base 1, the boss I6 engages the flared portion I5of ring I and expands the said ring sufficiently to allow it to embraceand tightly grip the base 'I as shown more clearly in Fig. 3. The puller2 is pushed down sufficiently so that the lower edge of the flaredportion I5 contacts with the upper surface of the socket I0 -or with thechassis in which the socket is -mounted. In this position, the rubberbuier I2 presses firmly against the bulb 8. Consequently, when thehandle 2 is tilted through a slight angle M (Figs. 4 and 5) ,g thefulcrum point is actually the lower edge of the flared portion I5 Whereit engages the socket I0. Consequently, the effective leverage 4on thetube is B (Fig. 4). This small tilting motion 'is therefore suflcient toproduce a vertical displacement of groove 6 with respect to member I3 asshown clearly in Fig. 5 so that when the handle is tilted back to thevertical `or to `a slight distance beyond the vertical, the member 5 isunlocked from the member II thus releasing the tube so that it can bepulled out of the socket with comparative ease by pulling vertically onthe hook portion 9 of the handle 2.

When the tube is thus removed, it remains rmly held in the tube pullerby reason of the frictional engagement between the split ring I and thetube base and by reason of the engagement between the buffer I2 and thebulb 8. The tube can therefore be expeditiously removed from its socketbyv a single nger' and without danger of the tube dropping from thepuller after removal.

When the tube has been pulled out of its socket, it can be removed fromthe puller 2 by gripping the portion I with the left hand while pressingdown on the top of `the bulb 8 with the thumb of the Aleft hand, theindex nger -of the right hand pulling outwardly on the hooked portion 9.

It will be understood of course that the invention is not ylimited tothe particular type of tube illustrated and that the *puller may beadvantageously used to extract other plugged-,in -devices from theirsockets whether these pluggedin devices be tubes, lamps, coils,condensers or other electrical circuit elements which are fric-Ationallyrheld in a plug-in type socket or receptacle.

Various changes and modiiications may be made in the typical embodimentdisclosed without departing from [the spirit and scope of the invention.Subject matter disclosed herein but not claimed, is claimed in DesignPatent No. 133,416.A

What I claim is: Y

l. A device for removing a pluggedin article from a plug-in receptacle,said device comprising a substantially tubular expansible portionadapted to telescope over and tightly grip the periph-V ery ofthearticle, and a pulling handle fastened to said tubular portion andextending along the article with a finger engaging portion at its upperend. 2. A device for removing a plugged-in article from a plug-inreceptacle, said devicevcompris ing a split cylinder of heavy springymetal, a vertically extending handle fastenedto the side of saidcylinder, said handle having a length which is 'much greater than theoverall length ofthe article and terminating at its upper end in a rigidringer hook. y

3. A device according to claim, 2 in which the said cylinder has anormal inside diameter which gage a side of the article during removalthereof. 6'. A device for removing a plugged-in article "from a plug-inreceptacle, said device comprising -alsubstantially tubular expansibleportion adaptdlto telescope over and tightly grip the periphery of thearticle, and a pulling handle fastened VtoY the said tubular portion,said tubular portion having an outwardly flared lower edge adapted Mtoengage the receptacle or its support to provide .an increased tiltingradius effective in removing the article from the receptacle.

RALPH S. MERKLE.

